CN105566098A - Method for combined production of high purity crystalline calcium acetate and waterless calcium acetate - Google Patents

Abstract

The invention relates to a method for combined production of high purity crystalline calcium acetate and waterless calcium acetate. The method comprises 1, weighing heavy calcium carbonate, adding acetic acid into the heavy calcium carbonate, heating and dissolving the mixture until CO2 is not escaped, and keeping a temperature of 80 DEG C for 20min, 2, adding a mixed impurity removal agent into the solution according to a ratio of 1: 2-3, controlling pH in a range of 11-12 and carrying out thermal insulation and sedimentation for 1-2h so that the impurities are precipitated in a form of hydroxides, 3, filtering the precipitates, collecting the filtrate, concentrating the filtrate at a temperature of 80-100 DEG C until a concentrating proportion of 1.18-1.30g/cm<3>, carrying out cooling to a temperature of 60 DEG C, filtering the precipitates to obtain a crystalline calcium acetate monohydrate and carrying out drying at a temperature of 60-70 DEG C, and 4, collecting the filtrate, carrying out concentration until the solution is in a viscous solid form so that waterless calcium acetate is obtained, and carrying out drying at a temperature of 90 DEG C. Through use of the mixed impurity removal agent, impurity removal is thorough and all calcium acetate can be produced. The method improves a yield, realizes zero discharge and realizes eco-friendly production.

Description

The co-production of a kind of high-purity crystallized lime acetate and anhydrous acetic acid calcium

Technical field

The invention belongs to chemical industry, food, medicine, chemical reagent field, the co-production of especially a kind of high-purity crystallized lime acetate and anhydrous acetic acid calcium.

Technical background

Crystallization lime acetate water white transparency liquid, anhydrous acetic acid calcium loose fines, odorless, mildly bitter flavor, soluble in water.Be widely used in food, pharmaceutical industries and chemical reagent, as mold inhibitor, buffer reagent, sweetener, sanitas, nutrition-fortifying agent and processing aid.Lime acetate is the high desirable calsium supplement of human absorptivity, can be used for the phosphoric acid salt combination for the treatment of hyperphosphatemia.

The production method of current domestic lime acetate has two kinds, one is by calcium carbonate and acetic acidreaction, one adopts calcium hydroxide and acetic acidreaction to obtain, because the foreign matter content of calcium hydroxide is higher, can not as the raw material producing highly purified lime acetate, with calcium carbonate as raw material, be also difficult to produce high purity lime acetate with general method.So choose raw material, research purification process, produces that impurity is applicable to food less, the high purity lime acetate of pharmaceutical grade is very important.

Summary of the invention

The object of the invention is to overcome the deficiencies in the prior art part, the co-production of a kind of high-purity crystallized lime acetate that method is simple, product purity is high, cost-saving and anhydrous acetic acid calcium is provided.

The object of the invention is to be achieved through the following technical solutions:

A co-production for high-purity crystallized lime acetate and anhydrous acetic acid calcium, is characterized in that: step is as follows:

(1) take water-ground limestone, then add acetic acid, heating for dissolving is extremely without CO ₂effusion, 80 DEG C of constant temperature 20min;

(2) in above-mentioned solution, add mixing cleaner, its ratio is=1:2-3, makes pH between 11-12, heat preservation settlement 1-2 hour, and such impurity is with precipitations such as oxyhydroxide;

(3) filtering-depositing, collects filtrate, concentrated at 80-100 DEG C, is 1.18-1.30g/cm3, is cooled to 60 DEG C, leaches precipitation, obtain a crystalline hydrate lime acetate, in 60-70 DEG C of drying when being concentrated to proportion;

(4) collect filtrate, continuing to be concentrated into solution is sticky solid shape, obtains anhydrous acetic acid calcium, in 90 DEG C of dryings.

And, described water-ground limestone: acetic acid weight ratio is 1:0.5-0.6.

And the step of described another kind of charging process is as follows:

(1) 1Kg water-ground limestone slowly joins in the glacial acetic acid of 1L80%, breaks into suspension;

(2) gradation adds 1Kg glacial acetic acid, is stirred to CO ₂effusion completely;

(3) add mixing cleaner in the solution, filter, filtrate is concentrated into thick, at 80 DEG C of collecting precipitations, obtains anhydrous acetic acid calcium, and its productive rate is 78%;

(4) collecting filtrate, is 1.3-1.4 being concentrated to proportion, and cool 20 DEG C, crystallization, filtering for crystallizing, dries naturally, obtains three crystalline hydrate lime acetates.

Advantage of the present invention and positively effect:

1, material choice method: the present invention is through test of many times, and select water-ground limestone to be that raw material is comparatively suitable, calcium carbonate has two kinds, light calcium carbonate and water-ground limestone.Light calcium carbonate is through prepared by reaction precipitation, and water-ground limestone is directly processed into through artificial separation from mineral reserve.Theoretically, light calcium carbonate say in quality better than water-ground limestone.But research finds, result is just in time contrary.Find that general industry light calcium carbonate is all through particle surface process, with the addition of some surface treatment, in the process of producing lime acetate, be difficult to removing, cause that to have produced lime acetate of poor quality.The present invention points out necessarily to select water-ground limestone just can produce highly purified lime acetate.Major impurity in water-ground limestone is oxide compound or the carbonate of Fe, Si, Al, Mg, Pb, Mn, also has fluorochemical, these impurity are when preparing lime acetate, if do not removed, capital more or less brings product into, make it the requirement that difficulty reaches food grade, pharmaceutical grade lime acetate, present invention also improves the minimizing technology of these impurity.

2, the application adopts a small amount of calcium hydroxide and sodium hydroxide mixing cleaner, and disposable removal of impurities successful methods is simple and easy to do, and removal of impurities is thorough.As can be seen from table 1 solubility product data, the solubility product of impurity phase is very little, and Ca (OH) ₂solubility product very large, so adopt the pH regulating lime acetate, effectively can remove the impurity such as Al, Fe, Mn, heavy metal, Pb, F-, make it reach high purity requirement, adopt a kind of feed hydrogen calcium oxide to carry out adjust ph and can reach the requirement removing above-mentioned impurity, but Ca (OH) ₂consumption very large, new impurity can be brought.This patent adopts CaO and sodium hydroxide mixing cleaner, reaches removal of impurities object like a bomb and namely decreases Ca (OH) ₂the introduction volume of middle impurity, again saves cost.

3, the impurity removal process of the application is simple, do not increase any impurity removal process, only need to add a certain amount of mixing cleaner, twice filtration is synthesized, owing to increasing mixing cleaner, the selection condition of oxide spinel calcium is relaxed, can be effectively cost-saving, practicable crystallization lime acetate simultaneously, the coproduction of anhydrous acetic acid calcium.

4, the present invention is because adding mixing cleaner, and removal of impurities is thorough, makes lime acetate can whole outputs, has not only added productive rate but also accomplished zero release, accomplished that environmental protection is produced.

Concrete embodiment

In order to understand the present invention, below in conjunction with embodiment, the invention will be further described: following embodiment is illustrative, is not determinate, can not limit protection scope of the present invention with following embodiment.

Embodiment 1

A co-production for high-purity crystallized lime acetate and anhydrous acetic acid calcium, step is as follows:

(1) take the water-ground limestone of 1Kg, then add 20wt% acetic acid 2.8L, heating for dissolving is extremely without CO ₂effusion, 80 DEG C of constant temperature 20min;

(2) in above-mentioned solution, add mixing cleaner, its ratio is=1:3, makes pH between 11-12, heat preservation settlement 1-2 hour, and such impurity is with precipitations such as oxyhydroxide;

Al ³⁺+3OH ^-→Al(OH) ₃

Mg ²⁺+2OH ^-→Mg(OH) ₂

Pb ²⁺+2OH ^-→Pb(OH) ₂

Mn ²⁺+2OH ^-→Mn(OH) ₂

2F ^-+Ca ²⁺→CaF ₂

SiO ^3-+Ca ²⁺→C _aSiO ₃

(3) filtering-depositing, collects filtrate, concentrated at 80-100 DEG C, being 1.28-1.30g/cm3, being cooled to 60 DEG C, leaching precipitation, obtaining a crystalline hydrate lime acetate when being concentrated to proportion, in 60-70 DEG C of drying, and productive rate 53%;

(4) collect filtrate, continuing to be concentrated into solution is sticky solid shape, obtains anhydrous acetic acid calcium, in 90 DEG C of dryings, and productive rate 45%.

Embodiment 2

A co-production for high-purity crystallized lime acetate and anhydrous acetic acid calcium, step is as follows:

(1) take 10Kg water-ground limestone, slowly add (30 liters) in 20% acetic acid, 80 DEG C of heated and stirred, about 30min

(2) in above-mentioned solution, add mixing cleaner=1:2, heat preservation settlement 1h, filter;

(3) filtrate is concentrated at 80 DEG C, when proportion is 1.18-1.28g/cm3, adds 300-320ml acetic acid, just has Precipitation, be cooled to 60-70 DEG C, leach precipitation, in 60-70 DEG C of drying, obtain a crystalline hydrate lime acetate, productive rate 55%;

(4) collect filtrate, this dries up to solution-based to continue concentrated (80 DEG C), and discharging, obtains anhydrous acetic acid calcium, productive rate 45%

Embodiment 3

A co-production for high-purity crystallized lime acetate and anhydrous acetic acid calcium, step is as follows:

(1) 1Kg water-ground limestone slowly joins in the glacial acetic acid of 1L80%, breaks into suspension;

(2) gradation adds 1Kg glacial acetic acid, is stirred to CO ₂effusion completely;

(3) add mixing cleaner in the solution, filter, filtrate is concentrated into thick, at 80 DEG C of collecting precipitations, obtains anhydrous acetic acid calcium, and its productive rate is 78%;

(4) collecting filtrate, is 1.3-1.4 being concentrated to proportion, and cool 20 DEG C, crystallization, filtering for crystallizing, dries naturally, obtains three crystalline hydrate lime acetates, productive rate 15%.

The solubility product difference table of table 1 impurity and calcium hydroxide

KspAl(OH) 3	1.9×10 -33
		KspFe(OH) 3	4×10 -38
KspMn(OH) 2	4.4×10 -14
		KspPb(OH) 2	1.6×10 -16

KspCaF 2	4.1×10 -11
		KspCa(OH) 2	4.7×10 -6
KspCaSiO 3	2.5×10

Claims (3)

1. a co-production for high-purity crystallized lime acetate and anhydrous acetic acid calcium, is characterized in that: step is as follows:

(1) take water-ground limestone, then add acetic acid, heating for dissolving is extremely without CO ₂effusion, 80 DEG C of constant temperature 20min;

(2) in above-mentioned solution, add mixing cleaner, its ratio is=1:2-3, makes pH between 11-12, heat preservation settlement 1-2 hour, and such impurity is with precipitations such as oxyhydroxide;

(3) filtering-depositing, collects filtrate, concentrated at 80-100 DEG C, is 1.18-1.30g/cm3, is cooled to 60 DEG C, leaches precipitation, obtain a crystalline hydrate lime acetate, in 60-70 DEG C of drying when being concentrated to proportion;

(4) collect filtrate, continuing to be concentrated into solution is sticky solid shape, obtains anhydrous acetic acid calcium, in 90 DEG C of dryings.

2. the co-production of high-purity crystallized lime acetate according to claim 1 and anhydrous acetic acid calcium, is characterized in that: described water-ground limestone: acetic acid weight ratio is 1:0.5-0.6.

3. the co-production of high-purity crystallized lime acetate according to claim 1 and anhydrous acetic acid calcium, is characterized in that: the step of described another kind of charging process is as follows:

(1) 1Kg water-ground limestone slowly joins in the glacial acetic acid of 1L80%, breaks into suspension;

(2) gradation adds 1Kg glacial acetic acid, is stirred to CO ₂effusion completely;

(3) add mixing cleaner in the solution, filter, filtrate is concentrated into thick, at 80 DEG C of collecting precipitations, obtains anhydrous acetic acid calcium, and its productive rate is 78%;

(4) collecting filtrate, is 1.3-1.4 being concentrated to proportion, and cool 20 DEG C, crystallization, filtering for crystallizing, dries naturally, obtains three crystalline hydrate lime acetates.